# Equivalent Feet of Straight Pipe

on . Posted in Pipe Layout Datasheets

When modeling a piping system, sometimes it is easier to model the entire system as a straight pipe and apply the flow equations to the pipe length.  The table below is what the equivalent straight line pipe can be used.  To use these, sum the amount of horizontal pipe plus the total equivalent length of sum of the fittings.  This will give you a reasonable approximation of the expected pressure drop through the pipe.  For more precise solutions, a flow modeling program should be used.

### Equivalent Feet of Straight Pipe

Pipe Size Inside Dia Gate or Ball Fully Open 90° Elbow Long Rad 90° or 45° Std Elbow Std Tee - Thru Flow Std Tee Branch Flow Close Return Bend Angle Valve Full open Globe Valve Full open Butterfly Valve 90° Weld Elbow Mitre Bend Swing Check
r/d = 1 r/d = 2 45° 90°
1/2 0.622 0.41 1.55 0.83 1.04 3.11 2.59 7.78 17.6           5.18
3/4 0.824 0.55 2.06 1.1 1.37 4.12 3.43 10.3 23.3           6.86
1 1.049 0.7 2.62 1.4 1.75 5.25 4.37 13.1 29.7           8.74
1 1/4 1.38 0.92 3.45 1.84 2.3 6.9 5.75 17.3 39.1           11.5
1 1/2 1.61 1.07 4.03 2.15 2.68 8.05 6.71 20.1 45.6           13.4
2 2.067 1.38 5.17 2.76 3.45 10.3 8.61 25.8 58.6 7.75 3.45 2.07 2.58 10.3 17.2
2 1/2 2.469 1.65 6.17 3.29 4.12 12.3 10.3 30.9 70 9.26 4.12 2.47 3.08 12.3 20.6
3 3.068 2.04 7.67 4.09 5.11 15.3 12.8 38.4 86.9 11.5 5.11 3.07 3.84 15.3 25.5
4 4.026 2.68 10.1 5.37 6.71 20.1 16.8 50.3 114 15.1 6.71 4.03 5.03 20.1 33.6
5 5.047 3.36 12.6 6.73 8.41 25.2 21 63.1 143 18.9 8.41 5.05 6.31 25.2 42.1
6 6.065 4.04 15.2 8.09 10.1 30.3 25.3 75.8 172 22.7 10.1 6.07 7.58 30.3 50.5
8 7.981 5.32 20 10.6 13.3 39.9 33.3 99.8 226 29.9 13.3 7.98 9.98 39.9 33.3
10 10.02 6.68 25.1 13.4 16.7 50.1 41.8 125 284 29.2 16.7 10 12.5 50.1 41.8
12 11.938 7.96 29.8 15.9 19.9 59.7 49.7 149 338 34.8 19.9 11.9 14.9 59.7 49.7
14 13.124 8.75 32.8 17.5 21.8 65.6 54.7 164 372 38.3 21.8 13.1 16.4 65.6 54.7
16 15 10 37.5 20 25 75 62.5 188 425 31.1 25 15 18.8 75 62.5
18 16.876 16.9 42.2 22.5 28.1 84.4 70.3 210 478 35.2 28.1 16.9 21.1 84.4 70.3
20 18.814 12.5 47 25.1 31.4 94.1 78.4 235 533 39.2 31.4 18.8 23.5 94.1 78.4
24 22.628 15.1 56.6 30.2 37.7 113 94.3 283 641 47.1 37.7 22.6 28.3 113 94.3
30 28 18.7 70 37.3 46.7 140         46.7 28 35 140
36 34 22.7 85 45.3 56.7 170         56.7 34 43 170
42 40 26.7 100 53.3 66.7 200         66.7 40 50 200
48 46 30.7 115 61.3 76.7 230         76.7 46 58 230

 Pipe Size Equivalent Length in terms of small d Entrance Exit Enlargement Contraction └── └── Sudden Std. Reducer Sudden Std. Reducer ◄▬ ▬► d/D = ¼ d/D = ½ d/D = ¾ d/D = ½ d/D = ¾ d/D = ¼ d/D = ½ d/D = ¾ d/D = ½ d/D = ¾ ┌── ┌── 1/2 1.7 1.1 0.38 1.3 0.38 0.9 0.63 0.38 0.38 1 2 3/4 2.5 1.5 0.51 1.7 0.51 1.3 0.9 0.51 0.51 1.5 2.8 1 3.2 2 0.7 2.3 0.7 1.8 1.3 0.7 0.7 2 4 1 1/4 4.8 3 1 3.3 1 2.2 1.8 1 1 2.7 5.5 1 1/2 5 3 1 4 1 3 2.2 1 1 3.3 6.8 2 7 4 1 5 1 3 3 1 1 4.5 9 2 1/2 8 5 2 6 2 4 3 2 2 5.5 11 3 10 6 2 8 2 5 4 2 2 9 18 4 12 8 3 10 3 6 5 3 3 10 20 6 18 12 4 14 4 9 7 4 4 1 17 33 8 25 16 5 19 5 12 9 5 5 2 23 46 10 31 20 7 24 7 15 12 6 6 2 30 60 12 37 24 8 28 8 18 14 7 7 2 40 80 14 42 26 9 20 16 8 42 84 16 47 30 10 24 18 9 50 100 18 53 35 11 26 20 10 60 120 20 60 38 13 30 23 11 70 1470 22 65 42 14 32 25 12 80 160 24 70 46 15 35 27 13 90 180

Tags: Pipe Tables